Delegate command not invoked

I have a silverlight 5 app using prism 4 and am having trouble with delegatecommand. I have used this feature before in other apps without any trouble but for some reason cannot get it to work in current app.

I'm setting loginCommand in constructor and put a messagebox(had to use messagebox as breakpoints are not been hit but that's another issue) in the LoginUser method that will/should be invoked when button is clicked.

Here's part of the LoginView with the delegate command attached to the button. Not sure what's going on here and have been looking at this to long now so hopefully someone can spot some silly mistake been made.

Based on my understanding, your problem might be related to the fact that the properties retrieved with the
[Import] attribute are not populated until after the constructor is completed. Hence your
DataContext is set with a null value.

To avoid this you could try using the [ImportingConstructor] attribute, for example like in the following code snippet: